2.

Posidonius informs us that Parmenides was the first to make this division of the earth into five zones, but that he almost doubled the size of the torrid zone, which is situated between the tropics, by bringing it beyond these into the temperate zones.626 But according to Aristotle the torrid zone is contained between the tropics, the temperate zones occupying the whole space between the tropics and the arctic circles.627 Both of these divisions Posidonius justly condemns, for the torrid zone is properly the space rendered uninhabitable by the heat. Whereas more than half of the space between the tropics is inhabited, as we may judge by the Ethiopians who dwell above Egypt. The equator divides the whole of this space into two equal parts. Now from Syene, which is the limit of the summer tropic, to Meroe, there are 5000 stadia, and thence to the parallel of the Cinnamon region, where the torrid zone commences, 3000 stadia. The whole of this distance has been measured, and it may be gone over either by sea or land; the remaining portion to the equator is, if we adopt the measure of the earth supplied by Eratosthenes, 8800 stadia. Therefore, as 16,800 is to 8800, so is the space comprised between the tropics to the breadth of the torrid zone.

If of the more recent measurements we prefer those which diminish the size of the earth, such as that adopted by Posidonius, which is about 180,000 stadia,628 the torrid zone will still only occupy half, or rather more than half, of the space comprised between the tropics; but never an equal space. [Respecting the system of Aristotle, Posidonius farther says,] “Since it is not every latitude which has Arctic Circles,629 and even those which do possess them have not the same, how can any one determine by them the bounds of the temperate zones, which are immutable?” Nothing however is proved [against Aristotle] from the fact that there are not Arctic Circles for every latitude, since they exist for all the inhabitants of the temperate zone, on whose account alone the zone receives its name of temperate. But the objection that the Arctic Circles do not remain the same for every latitude, but shift their places, is excellent.630